$NetBSD$

--- src/VBox/Runtime/r0drv/netbsd/spinlock-r0drv-netbsd.c.orig	2016-07-07 07:08:46.986058035 +0000
+++ src/VBox/Runtime/r0drv/netbsd/spinlock-r0drv-netbsd.c
@@ -0,0 +1,209 @@
+/*  spinlock-r0drv-netbsd.c $ */
+/** @file
+ * IPRT - Spinlocks, Ring-0 Driver, NetBSD.
+ */
+
+/*
+ * Copyright (c) 2007 knut st. osmundsen <bird-src-spam@anduin.net>
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following
+ * conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+
+/*********************************************************************************************************************************
+*   Header Files                                                                                                                 *
+*********************************************************************************************************************************/
+#include "the-netbsd-kernel.h"
+#include "internal/iprt.h"
+
+#include <iprt/spinlock.h>
+#include <iprt/err.h>
+#include <iprt/alloc.h>
+#include <iprt/assert.h>
+#include <iprt/asm.h>
+#include <iprt/asm-amd64-x86.h>
+#include <iprt/thread.h>
+#include <iprt/mp.h>
+
+#include "internal/magics.h"
+
+
+/*********************************************************************************************************************************
+*   Structures and Typedefs                                                                                                      *
+*********************************************************************************************************************************/
+/**
+ * Wrapper for the struct mtx type.
+ */
+typedef struct RTSPINLOCKINTERNAL
+{
+    /** Spinlock magic value (RTSPINLOCK_MAGIC). */
+    uint32_t volatile   u32Magic;
+    /** The spinlock. */
+    uint32_t volatile   fLocked;
+    /** Saved interrupt flag. */
+    uint32_t volatile   fIntSaved;
+    /** The spinlock creation flags. */
+    uint32_t            fFlags;
+#ifdef RT_MORE_STRICT
+    /** The idAssertCpu variable before acquring the lock for asserting after
+     *  releasing the spinlock. */
+    RTCPUID volatile    idAssertCpu;
+    /** The CPU that owns the lock. */
+    RTCPUID volatile    idCpuOwner;
+#endif
+} RTSPINLOCKINTERNAL, *PRTSPINLOCKINTERNAL;
+
+
+RTDECL(int)  RTSpinlockCreate(PRTSPINLOCK pSpinlock, uint32_t fFlags, const char *pszName)
+{
+    RT_ASSERT_PREEMPTIBLE();
+    AssertReturn(fFlags == RTSPINLOCK_FLAGS_INTERRUPT_SAFE || fFlags == RTSPINLOCK_FLAGS_INTERRUPT_UNSAFE, VERR_INVALID_PARAMETER);
+
+    /*
+     * Allocate.
+     */
+    AssertCompile(sizeof(RTSPINLOCKINTERNAL) > sizeof(void *));
+    PRTSPINLOCKINTERNAL pThis = (PRTSPINLOCKINTERNAL)RTMemAllocZ(sizeof(*pThis));
+    if (!pThis)
+        return VERR_NO_MEMORY;
+
+    /*
+     * Initialize & return.
+     */
+    pThis->u32Magic  = RTSPINLOCK_MAGIC;
+    pThis->fLocked   = 0;
+    pThis->fFlags    = fFlags;
+    pThis->fIntSaved = 0;
+
+    *pSpinlock = pThis;
+    return VINF_SUCCESS;
+}
+
+
+RTDECL(int)  RTSpinlockDestroy(RTSPINLOCK Spinlock)
+{
+    /*
+     * Validate input.
+     */
+    RT_ASSERT_INTS_ON();
+    PRTSPINLOCKINTERNAL pThis = (PRTSPINLOCKINTERNAL)Spinlock;
+    if (!pThis)
+        return VERR_INVALID_PARAMETER;
+    AssertMsgReturn(pThis->u32Magic == RTSPINLOCK_MAGIC,
+                    ("Invalid spinlock %p magic=%#x\n", pThis, pThis->u32Magic),
+                    VERR_INVALID_PARAMETER);
+
+    /*
+     * Make the lock invalid and release the memory.
+     */
+    ASMAtomicIncU32(&pThis->u32Magic);
+    RTMemFree(pThis);
+    return VINF_SUCCESS;
+}
+
+
+RTDECL(void) RTSpinlockAcquire(RTSPINLOCK Spinlock)
+{
+    PRTSPINLOCKINTERNAL pThis = (PRTSPINLOCKINTERNAL)Spinlock;
+    RT_ASSERT_PREEMPT_CPUID_VAR();
+    AssertPtr(pThis);
+    Assert(pThis->u32Magic == RTSPINLOCK_MAGIC);
+
+    if (pThis->fFlags & RTSPINLOCK_FLAGS_INTERRUPT_SAFE)
+    {
+        for (;;)
+        {
+            uint32_t fIntSaved = ASMIntDisableFlags();
+            critical_enter();
+
+            int c = 50;
+            for (;;)
+            {
+                if (ASMAtomicCmpXchgU32(&pThis->fLocked, 1, 0))
+                {
+                    RT_ASSERT_PREEMPT_CPUID_SPIN_ACQUIRED(pThis);
+                    pThis->fIntSaved = fIntSaved;
+                    return;
+                }
+                if (--c <= 0)
+                    break;
+                cpu_spinwait();
+            }
+
+            /* Enable interrupts while we sleep. */
+            ASMSetFlags(fIntSaved);
+            critical_exit();
+            DELAY(1);
+        }
+    }
+    else
+    {
+        for (;;)
+        {
+            critical_enter();
+
+            int c = 50;
+            for (;;)
+            {
+                if (ASMAtomicCmpXchgU32(&pThis->fLocked, 1, 0))
+                {
+                    RT_ASSERT_PREEMPT_CPUID_SPIN_ACQUIRED(pThis);
+                    return;
+                }
+                if (--c <= 0)
+                    break;
+                cpu_spinwait();
+            }
+
+            critical_exit();
+            DELAY(1);
+        }
+    }
+}
+
+
+RTDECL(void) RTSpinlockRelease(RTSPINLOCK Spinlock)
+{
+    PRTSPINLOCKINTERNAL pThis = (PRTSPINLOCKINTERNAL)Spinlock;
+    RT_ASSERT_PREEMPT_CPUID_SPIN_RELEASE_VARS();
+
+    AssertPtr(pThis);
+    Assert(pThis->u32Magic == RTSPINLOCK_MAGIC);
+    RT_ASSERT_PREEMPT_CPUID_SPIN_RELEASE(pThis);
+
+    if (pThis->fFlags & RTSPINLOCK_FLAGS_INTERRUPT_SAFE)
+    {
+        uint32_t fIntSaved = pThis->fIntSaved;
+        pThis->fIntSaved = 0;
+        if (ASMAtomicCmpXchgU32(&pThis->fLocked, 0, 1))
+            ASMSetFlags(fIntSaved);
+        else
+            AssertMsgFailed(("Spinlock %p was not locked!\n", pThis));
+    }
+    else
+    {
+        if (!ASMAtomicCmpXchgU32(&pThis->fLocked, 0, 1))
+            AssertMsgFailed(("Spinlock %p was not locked!\n", pThis));
+    }
+
+    critical_exit();
+}
